Disposal of hypodermic syringes having needles attached to them, presents a serious risk of infection to the handlers, especially if they should accidentally prick themselves on one of the needles.
Various forms of apparatus have therefore previously been is proposed that pass a current through the needles to destroy them, this being commonly termed needle incineration. The current not only melts the needles to prevent them from pricking a handler of the waste hypodermic syringes, but also burns off any toxic residue on the needles.
Such apparatus usually has two spaced electrodes that apply a low voltage across a short length of the needle near its tip and the high current that flows melts this section of the needle. The needle is then progressively fed through the gap between the electrodes to melt the whole of the needle down to the collar that is fitted to the syringe.
The electrodes that are used to pass a current through the needles tend to corrode with time and to facilitate their replacement it has been proposed in GB-A-2,278,986 to mount the electrodes on a cartridge-like electrode plate unit having syringe insertion holes. This facilitates the task of clearing debris from the vicinity of the electrodes, which will themselves be contaminated with pathogens, the debris from the needles is stored in an open box which still presents a hazard to the person emptying the incineration apparatus as it fills up with use, because the debris and the box are contaminated both from any drips from the syringe and from the aerosol action.
U.S. Pat. No. 5,076,178 discloses an apparatus that has an incinerator housing that is separate from a power supply housing and from a drawer for storing the hypodermic syringes. Though termed an incinerator housing, the incineration electrodes and a sealing crimp do not in fact form part of the incinerator housing but remain attached to the power supply housing when the incinerator housing is withdrawn for emptying. The apparatus does not therefore avoid the possibility of contamination by coming into contact with the needle debris.
A further apparatus, disclosed in U.S. Pat. No. 4,877,934, has a drawer with an elongate slot in its top surface alongside which one of the electrodes is provided to contact the needle to be incinerated near to the hub. A second electrode is disposed on a ramped surface on the bottom of the drawer opposite the elongate slot. In use, the needle is moved along the elongate slot and first heated over its entire length. As the needle is incinerated it is moved up the ramp to destroy to reduce its length progressively.
The drawer in this case is not permanently closed because debris can escape from the drawer. Furthermore, one of the electrodes, which can itself be contaminated, is exposed on the upper surface of the drawer. For this reason, a cover needs to be fitted to seal the top of the drawer for safety before it is discarded.